Vibrators

ABSTRACT

A vibrator, such as used in concrete mixes, comprises a cylindrical casing in which a rotor in the form of a pendular mass is suspended and rotatably driven. The rotor is causes to gyrate in rolling contact in the casing by coacting lobes and recesses, and these lobes and recesses are located intermediately between the ends of the pendular rotor, e.g. at about two-fifths of the length of the rotor from its free end.

United States Hate-ht Primary ExaminerPaul R. Gilliam Attorney-Young & Thompson ABSTRACT: A vibrator, such as used in concrete mixes, comprises a cylindrical casing in which a rotor in the form of a pendular mass is suspended and rotatably driven. The rotor is causes to gyrate in rolling contact in the casing by coacting lobes and recesses, and these lobes and recesses are located intermediately between the ends of the pendular rotor, eg. at about two-fifths of the length of the rotor from its free end.

[72] inventor Percival George Hunter New Malden, Surrey, England [21] Appl. No. 839,604

[22] Filed Ju1y7, 1969 [45] Patented Sept. 28, 1971 [73] Assignee Fyne Machinery & Engineering Limited London, England [32] Priority May 2, 1968 [33] Great Britain [54] VIBRATORS 1 Claim, 3 Drawing Figs. I

[52] 11.5.0 259/1 [51] 1nt.C1 1301f,

[50] Field of Search 259/1 PATENTEU SEP28 I9?! Sum 2 OF 2 lnvenlor PER 0 WM e'aeatA umrze By W 17% Attorneys VIBRATORS This invention relates to vibrators, and more especially to immersion vibrators, used for vibrating concrete mix in situ, and like operations.

The invention consists in a vibrator comprising an outer casing, a pendulumtype rotor pivotally mounted in the casing, with smooth surface contact between a peripheral zone of said rotor and the inner area of the casing, in the neighborhood of the free end of the rotor, and positive drive cooperating means respectively on the rotor and easing at a point intermediate the length of the rotor.

The positive drive cooperating means may comprise outwardly projecting lobes on the rotor adapted to engage channels on the inner casing surface, as disclosed on British Patent specification Nos. 1,030,360, and 1,135,035. These means may be dimensioned to ensure continuous true rolling engagement when the rotor is set into rotation in the casing. The means may be in the form of a comparatively short ring or sleeve located at an intermediate position, e.g. approximately the midpoint, of the length of the pendular rotor. At its free end of the rotor may be formed with an enlarged head.

The invention will clearly understood from the following description of one form (given, however, merely by way of example) which it may assume, and this description will be more readily followed by reference to the accompanying drawings wherein FIG. 1 represents a longitudinal sectional view of a vibrator in accordance with the invention:

FIG. 2 represents an enlarged transverse action in the plane A-A of FIG. 1: and

HG. 3 represents enlarged in axial cross section further constructional details of a vibrator in accordance with the invention.

ln carrying the invention into effect in one convenient manner, as shown in FIGS. 1 and 2 of the aforesaid drawings, an immersion vibrator comprises a headpiece 1 on which is mounted a tubular metal body 2, fitted at its other end with a nosepiece 3. ln an axial bore in the headpiece 1 a driving shaft 4 is mounted in bearings 5 and fitted with oil seals 6.

An eccentric rotor attached to the drive shaft 4 by a universal joint 7 comprises a rod having at its free end an attached or integral enlarged rotor head 9. This head 9 projects into a larger cylindrical recess 10 in the inner face of the nosepiece 3, and a smooth cylindrical surface 11 on the periphery of the rotor head is in contact with a corresponding smooth surface on the wall of this recess.

At a point intermediate the length of the pendular rotor 8, 9 (e.g. in the neighborhood of its midpoint as illustrated) continuous rolling engagement between the casing and the rotor (when the latter is set into rotation) is ensured by cooperating parts provided with coacting ribs or lobes, and channels or recesses. Arrangements of this character are described and illustrated in British Pat. specification Nos. 1,030,360, and 1,135,035. One form of such an arrangement suitable for use in the present invention is illustrated in cross section in FIG. 2 of the aforesaid drawings, and comprises a number, e.g. four, of ribs or lobes l2, angularly equispaced round the rotor rod 8 located in a stator surround 13 formed with a different number of channels or recesses in which the ribs or lobes 12 can engage. The transverse dimensions of this lobed portion of the rotor, i.e. the distance between opposite rotor tips, is selected to be only slightly less that the distance between the low point of a channel or recess, and the diametrically opposite wall surface, so that disengagement of the rotor and surround is prevented. Thus when the rotor is set into rotation by the shaft 4 the ribs or lobes maintain a continuous true rolling engagement in the surround 13. Either or both the ribbed pordesired, along the length of the rotor.

When the vibrator IS in use the rotor rod 8 is set into rotation by the drive shaft 4 connected to any suitable drive (e.g. a flexible cable) and the rotating mass sets up vibrations. A stepup ratio between the driven frequency and the generated vibrations is introduced by the cooperating lobes and channels. The amplitude of movement of the head 9, and thus of the generated vibrations is a function of the length of the rotor rod 8 extending beyond the stator 13, and by suitable choice of dimensions vibrations of any desired amplitude may be set up, (subject to appropriate allowance or adjustment of dimensions of the rotor head 9 and its recess 10). An oil reservoir may be provided in the recess 10, and the stator surround 13 and the lobed rotor are normally sufficiently lubricated by a mist of oil from the reservoir.

Constructional details of one convenient form of vibrator according to the invention are shown in grater detail in FIG. 3 of the drawings. The drive shaft (indicated by reference 4 in F IG. 1) is built up of a hollow stepped tube 15 screwed on to a female universal coupling member 16 which engages with a male universal coupling member 17 screwed on to the rotor shaft 8. In the upper end of the casing 71 needle bearings 19 in two races separated by a spacer 20 accommodate the primary shaft 15, which abuts an annular thrust plate 21 against which the oil seal 6 is held by a screwed-in end cap 22.

The lobes or ribs 12 are preferably integral with the rotor shaft 8. The cooperating stator ring 13 may be clamped between steps 23 adjacent to the ends of two separable portions of the casing 2 adapted to screw together as shown at 24. The pendulum head 9 (not shown in Fig. 3) is preferably an integral part of the shaft 8, but may be separately formed and secured to the shaft.

From the above description it will be :seen that the invention provides a versatile and effective vibrator, but it should be understood that the invention is not limited solely to the details of the form described above which many be modified, in order to meet various conditions and requirements encountered, without departing from the scope of the invention. As an advantage of the above described vibrator construction it may be noted that since the rotor head 9 by its surface 11 bears against the casing in the recess 10, the cooperating stator 13 and rotor 12 are relieved of heavy radial loads, which reduces wear.

What we claim is:

1. A vibrator comprising an outer casing, a drive shaft mounted in bearings in the casing, a rotor connected at one end to said drive shaft by a universal joint, said rotor being a shaft having an enlarged mass at its end opposite said universal joint, the casing surrounding said enlarged mass having an internal diameter greater than the external diameter of said enlarged mass so that the rotor gyrates in the casing, the facing surfaces of the said enlarge mass and said casing being smooth, the peripheral area of said universal joint having projections thereon in the form of a plurality of equispaced recesses therein of a number greater that the number of said teeth for receiving said teeth, said lobes and recesses having curved surfaces to ensure a relatively rolling action during gyratory movement of the rotor, the external dimensions of the lobed zone of the rotor and the internal dimensions of the recessed portion of the casing being such that said lobes and recesses cannot become engaged from mesh during said gyratory movement. 

1. A vibrator comprising an outer casing, a drive shaft mounted in bearings in the casing, a rotor connected at one end to said drive shaft by a universal joint, said rotor being a shaft having an enlarged mass at its end opposite said universal joint, the casing surrounding said enlarged mass having an internal diameter greater than the external diameter of said enlarged mass so That the rotor gyrates in the casing, the facing surfaces of said enlarged mass and said casing being smooth, the peripheral area of said rotor intermediate said enlarged mass and said universal joint having projections thereon in the form of a plurality of equispaced lobes projecting in the manner of teeth from said rotor, the area of said casing surrounding said lobes having a plurality of equispaced recesss of a number greater than the number of said teeth for receiving said teeth, said lobes and recesses having curved surfaces to ensure a relatively rolling action during gyratory movement of the rotor, the external dimensions of the lobed zone of the rotor and the internal dimensions of the recessed portion of the casing being such that said lobes and recesses cannot become engaged from mesh during said gyratory movement. 